For example: - You once lied. - You are therefore a liar. Perhaps not a very good example, but the premise is the same; they will attack a single manifestation of something as though it were a microcosm of everything else. What is this called? I first thought it was somewhat of a straw man argument, but I'm not certain. It happens a lot in arguments, because someone will take one instance out of many to negate all else. Make sense?